Lots of errant information on this thread. There is No law that you must give your SSN to a doctor or hospital. And contrary to a post, there also is no law that says they cannot ask you for it. You cannot sue because they asked you for your SSN [ok you can sue but you have no case] I have refused to give mine out for well over two decades. Yes the doctor could refuse to accept you as a patient. A doctor can refuse a patient for any reason. A hospital cannot.

If you try to "turn them in for trying to steal your identity" you will be laughed at, deservedly.

Someone posted that the doctor gets your SSN from your insurance company anyhow. That is wrong. The insurance company does not share that information, and if you are smart, you never gave it to the insurance company when you got the coverage.

There is no reason to give them the last four numbers, or any numbers.

Maybe to do with medicare claims?

The reason they want your SSN is if your account goes to collections for bad debt the collection agency has to have the number to track you.

That's pretty stupid reasoning there.

By your logic, all they need is a name and social security number and they can go after your debt.

But if that were true, I'd just give them a fake social security number every time. They don't check to confirm that the number you give them is correct.

They do, however, check your ID. And they do verify your insurance, if you have any.

Neither drivers' license nor insurance cards have a social security number on them. I haven't provided a social security number to any physician of any kind on any form since I was in my 30's. They have no need for it and haven't had a need for it, even when I was insured (because my insurance has always had a unique ID number).